1. Field of the Invention
The present invention relates to an ultrasonic image generating apparatus and an ultrasonic image generating method of generating an image based on a signal received from an ultrasonic sensor such as an ultrasonic apparatus.
2. Description of the Related Art
Apparatus sending sound, receiving a reflected wave from a subject and generating an image from a received signal thereof may be defined as an ultrasonic apparatus. The ultrasonic apparatus can conventionally obtain a two-dimensional tomographic image of an object non-invasively and in real time, and for instance, it has come into widespread use in clinical medicine as an indispensable apparatus because of its high safety to a living body, and the same advantages can be said in other fields.
In general, to generate the fault image, the ultrasonic apparatus receives an echo obtained by having a part of an ultrasonic wave sent from an ultrasonic probe (having an ultrasonic wave sending portion and a sound receiving portion) reflected in a change point (change face) of an organizational structure inside an object which is the subject (refer to Electric Industries Association of Japan Corporation, xe2x80x9cHandbook of Ultrasonic Diagnostic Equipmentsxe2x80x9d, Colona Publishing, Co., Ltd. for instance).
Here, FIG. 27 schematically shows a structure of an ultrasonic wave sending portion and an ultrasonic wave receiving portion of an ultrasonic probe 2701. The ultrasonic wave sending portion and the ultrasonic wave receiving portion have the structure wherein a plurality of miniscule oscillation elements 2702 of generating the ultrasonic wave and receiving the ultrasonic wave to oscillate are arranged in one horizontal row. The ultrasonic wave sending portion is means of oscillating the ultrasonic wave from a row 2703 of a predetermined number (six in the drawing) of oscillation elements, and a wave front of the ultrasonic wave oscillated from each oscillation element forms one ultrasonic beam. At this time, a path length of the ultrasonic wave oscillated to a focus (or a focal range of a fixed length) of one ultrasonic beam from each oscillation element is different form one another. For instance, as shown in the drawing, in the row of oscillation elements 2703, a path length Pa of an oscillation element 2702a which is the closest to a focus 2704 is shorter than a path length Pb of an oscillation element 2702b which is the farthest from a focus 2704.
Thus, to form one ultrasonic beam, timing of ultrasonic wave oscillation of the oscillation element 2702b is rendered earlier than that of the oscillation element 2702a so that both ultrasonic waves simultaneously reach the focus 2704.
In the ultrasonic wave sending portion, the position of the row of oscillation elements 2703 is further moved from one end to the other end piece by piece of the oscillation element 2702. The ultrasonic beam thereby scans in the unit of the oscillation element 2702, so that an ultrasonic wave outgoing area substantially having a fixed width is formed. If there is the object in the ultrasonic wave outgoing area, the echo is generated on its surface and is received by the ultrasonic probe as ultrasonic wave receiving portion 2701 so that the fault image of the object is formed. Moreover, here, the ultrasonic wave receiving portion is the oscillation element 2702 functioning therein after outputting the ultrasonic wave. That is, the oscillation elements 2703 are used in common by the ultrasonic wave sending portion and the ultrasonic receiving portion.
As this reflected wave is of small magnitude compared to a sending wave, it is amplified when generating an image. To adjust this amplification degree, that is, to adjust image quality, a gain level is conventionally adjusted by a plurality (16 for instance) of sliders classified by depth of the object called STC (Sensitivity Time Control), which adjustment is manually performed by a user. In addition, it is also generally processed by a logarithm amplifier.
As described above, the amplification of the ultrasonic apparatus of the past is generally performed manually by the user while seeing a displayed image, starting with control of an STC level and a dynamic range
However, there has been a problem that the aforementioned control of the image quality is complicated and requires experience. In addition, there are the cases where, depending on properties of an inspection subject, propagation of an ultrasonic signal is not good, a signal level of a received ultrasonic signal drops and the entire image cannot easily obtain contrast. Such problems on the image quality have sometimes taken a long time to solve because the work of displaying the image once, changing a parameter while seeing the image and approaching target image quality in order is necessary.
In addition, there has been the following problem. The ultrasonic wave generates the echo if it hits the change point (change plane) of the organizational structure inside an object which is the subject. At this time, behavior of the ultrasonic wave thereafter is different according to hardness of the organizational structure and so on.
For instance, in the case where a soft organization such as an internal organ is the object, a part of the ultrasonic wave is reflected on the change face but another part is further propagated beyond the change face. And in the case where there is a new object beyond it, the ultrasonic wave is reflected on the new object so as to form a further new image.
Yet, there are the cases where the entire ultrasonic wave is reflected on the surface of the object when a hard organization such as a bone or a stone is the object. To be more specific, as shown in FIG. 28, in the case where the entire ultrasonic wave striking a change face 2803 of an object 2802 is reflected on the side of the probe in an imaging subject area 2801 formed by the ultrasonic beam emitted from the ultrasonic probe 2701, the area right behind the object 2802 becomes a shielded area 2804 passed through by no ultrasonic beam and having no information as the image. Therefore, it is not possible to know what is there, and for instance, whether or not there is further an object which is the subject.
To delete the disadvantage, the user has only to change a position of the ultrasonic probe 2701. To do so, however, the user needs to visually check on the screen to see which portion of the image is the shielded area 2804, and it takes time and effort. In addition, correspondence between an original image and the image after changing the position of the ultrasonic probe 2701 becomes unclear, and so reliability of obtainable information as a whole is reduced.
An object of the present invention is, in consideration of such problems of an image display apparatus of the past, to obtain the ultrasonic image generating apparatus and the ultrasonic image generating method capable of thoroughly obtaining the image in an imaging area while saving time and effort for operation on the user side and reducing the area where the ultrasonic wave is shielded by an imaging target.
Another object of the invention is to provide the image display apparatus and so on capable of adjusting the image quality in real time and performing the work of image adjustment which required experience in the past automatically and in a short time.
The 1st invention of the present invention is an ultrasonic image generating apparatus comprising:
ultrasonic beam outputting means of outputting an ultrasonic beam to a predetermined subject area;
ultrasonic beam receiving means of receiving a reflected ultrasonic beam which is a reflected wave of said ultrasonic beam obtained from said subject area;
image generating means of generating an image based on the reflected ultrasonic beam received by said ultrasonic beam receiving means; and
ultrasonic beam output direction controlling means of performing control of changing an outgoing direction of the ultrasonic beam of said ultrasonic beam outputting means to said subject area.
The 2nd invention of the present invention is the ultrasonic image generating apparatus according to the 1st invention, wherein said ultrasonic beam output direction controlling means electrically controls said change.
The 3rd invention of the present invention is the ultrasonic image generating apparatus according to the 1st invention, further comprising image analyzing means of analyzing the image generated by said image generating means,
wherein the ultrasonic beam output direction controlling means controls said change based on analysis results of said image analyzing means.
The 4th invention of the present invention is the ultrasonic image generating apparatus according to the 3rd invention,
wherein said image analyzing means analyzes whether or not there is a predetermined imaging target in said subject area, and in the case where there is said imaging target, analyzes whether or not there is a shielded area in which said ultrasonic beam is shielded by said imaging target in said subject area, and
in the case where there is said shielded area, said ultrasonic beam output direction controlling means controls said change so that the area to be passed through by the ultrasonic beam emitted from said ultrasonic beam outputting means next includes a part of said shielded area.
The 5th invention of the present invention is the ultrasonic image generating apparatus according to the 1st invention, further comprising reflected ultrasonic beam analyzing means of analyzing the reflected ultrasonic beam received by said ultrasonic beam receiving means,
wherein said ultrasonic beam output direction controlling means controls said change based on analysis results of said reflected ultrasonic beam analyzing means.
The 6th invention of the present invention is the ultrasonic image generating apparatus according to the 5th invention,
wherein said reflected ultrasonic beam analyzing means analyzes whether or not there is a non-detected area in which no reflected ultrasonic beam is detected in said subject area, and
in the case where there is said non-detected area, said ultrasonic beam output direction controlling means controls said change so that the area to be passed through by the ultrasonic beam emitted from said ultrasonic beam outputting means next includes a part of said non-detected area.
The 7th invention of the present invention is the ultrasonic image generating apparatus according to the 6th invention,
wherein said subject area is determined to be within a distance capable of detecting said reflected ultrasonic beam at a predetermined intensity.
The 8th invention of the present invention is an ultrasonic image generating method comprising:
an ultrasonic beam outputting step of outputting an ultrasonic beam to a predetermined subject area;
an ultrasonic beam receiving step of receiving a reflected ultrasonic beam which is a reflected wave of said ultrasonic beam obtained from said subject area;
an image generating step of generating an image based on the reflected ultrasonic beam received by said ultrasonic beam receiving step; and
an ultrasonic beam output direction controlling step of performing control of changing an outgoing direction of the ultrasonic beam of said ultrasonic beam outputting step to said subject area.
The 9th invention of the present invention is the ultrasonic image generating method according to the 8th invention,
wherein said ultrasonic beam output direction controlling step electrically controls said change.
The 10th invention of the present invention is the ultrasonic image generating method according to the 8th invention, further comprising an image analyzing step of analyzing the image generated by said image generating step, and wherein the ultrasonic beam output direction controlling step controls said change based on analysis results thereof.
The 11th invention of the present invention is the ultrasonic image generating method according to the 8th invention, further comprising a reflected ultrasonic beam analyzing step of analyzing the reflected ultrasonic beam received by said ultrasonic beam receiving step, and wherein said ultrasonic beam output direction controlling step controls said change based on analysis results thereof.
The 12th invention of the present invention is a program of causing a computer to function as the image analyzing means of analyzing the image generated by said image generating means of the ultrasonic image generating apparatus according to the 3rd invention and the ultrasonic beam output direction controlling means of controlling said change based on the analysis results of said image analyzing means.
The 13th invention of the present invention is a program of causing a computer to function as the reflected ultrasonic beam analyzing means of analyzing the reflected ultrasonic beam received by said ultrasonic beam receiving means of the ultrasonic image generating apparatus according to the 5th invention and the ultrasonic beam output direction controlling means of controlling said change based on the analysis results of said reflected ultrasonic beam analyzing means.
The 14th invention of the present invention is a medium having a program according to the 12th invention and processable by a computer.
The 15th invention of the present invention is a medium having a program according to the 13th invention and processable by a computer.